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SS2 - Balboa Island Seawall - PowerPoint (Staff)
Balboa Islands Seawall Rehabilitation Project Rehabilitation Options July 14, 2015 Agenda Item No. SS2 City Council Study Session July 14, 2015 Table of Contents ➢ Background & Existing Condition of Seawalls — p. 3 ➢ Structural Integrity of the Seawalls — p. 19 Addressing Over -topping of Seawalls — p. 29 Tidelands Management Committee Review — p. 52 ➢ Minimum Top -of -Wall Elevation — p. 58 Seawall Replacement Options — p. 59 ➢ Funding — p. 82 ➢ Appendices — p.87 • Ferry Landing • Jetty Tide Gate • Storm Drain Collection System • ADA and Beach Access Public and Private Pier Connections FEMA Flood Plain Background Information: Public and Private Seawalls & Bulkheads (^'18 linear miles) ••-+............. Background Information: City -Owned Seawalls (— 3 linear miles) Balboa Islands account for about 2 miles. 11 Overview of Balboa Islands Background Information Balboa Islands are protected from flooding by seawalls that encircles both islands. Grand Canal Seawalls were built in 1929. West End Seawall were built in ^'1925-1935. Remainder of seawall were built in N1939 The Balboa Islands are the lowest of the eight islands in the harbor: approximately Elevation 5'-7' (Extreme high tides approach 8'.) Reference Newport Harbor Island Land Elevations Elevations Balboa Islands 5'-7' (NAVD88) Lido Island 12'-13' Harbor Island 10'-11' Bay Island 10'-11' Linda Island 9'-10' Newport Island 10' Collins Island 8'-9' Top of Wall Elevations at Other Locations County of Orange (Dana Point): 9.62' County of LA (Marina del Rey City of Huntington Beach (General) City of Long Beach (Alamitos Bay) City of Long Beach (Naples Island) Balboa Island: Little Island: 9.62' - 11.62 9.62' 9.62' 9.50' 7.7' - 8.7' 8.5' - 9.3' Low -Lying Areas Around the Harbor 6047500 6050000 6052500 6055000 W57500 6060000 6062500 6065000 W67500 dSJ Feet (NAVD 88) 4-5 5-6 6-7 7-8 18-9 9-10 10-11 11-12 12-13 13-14 14-15 15-16 16-17 17-18 18-19 _ 19-20 �n ,/`� Background Information Existing Wall Condition . Existing walls are between 76 to 86 years old. 2. Original design lifespan was probably about 75 years. 3. Walls are exhibiting obvious signs of deterioration and stress. 4. Existing walls subject to Seismic Risk. 5. Grand Canal: Depth of wall below mudline is very shallow. 6. Many unknowns on the condition of the: (a) seawall steel reinforcement, (b) soldier piles, (c) walls below the mudline, and (d) seawall tiebacks. 7. Useful remaining lifetime? Per a City seawall assessment report (201 1) - perhaps as little as 10 years; maybe as much as 25 years. 9 Background Information Existing Wall Condition There have been a string of repair/maintenance projects over past 40 years: • Grand Canal Seawall Coping Repair/Sealing ('76,78,79,'80) • West End/Grand Canal Spot Sidewalk Grouting/Compaction ('80) • Grand Canal Seawall Plaster Sealing ('81) • Grand Canal Seawall and Sidewalk Joint/Void Grouting ('83) • NewTie Rod Installation/Deadman Spot Repair E/oAgate ('87) • West End Wall Stabilization: Rock Armor at Toe, Earth Anchors, Void Grouting ('87) • Island Wide Spot Seawall Repair and Joint/Crack Sealing (2003- 2007, 2009 -present) Rock Ballast Replaced at Corners of Grand Canal and Little Island for Support (2000) Rock Ballast Placed at West End for Support (1985) Earth Anchors installed E/o Balboa Island Ferry Landing - South Bay Front (1987) 1 0%, -; 4 it p .�. - . L 12 a •w Wall Movement (West End) Pile Cracks (West End) MOW Grand Canal: Spalling Veneer Grand Canal: Spalled Veneer .4"mm"r Grand Canal: Spalled Veneer on Soldier Pile n:. n:. Grand Canal: Cap Veneer Spalled 17 Balboa Islands — Seawall Structural Integrity and Over -Topping Assessment Study Completed April 2011 Seawall Condition AND PDMEfNT OF SEAWALL NTML FOR SEAWALLftOVER�OPPING INTEGftITY Bp(6M �.Ip� • Seawall Age: 76-86 years l•I �Ij�.1 JIiA. M/nl REPM+t 1, 4 Cp et MewW.10. ���_ M1 I ConsYMnb.IM l lnbm.IFn. m—fnlm N� fln�$ITUWM.LLC A,'"m„ Overall Condition: Holding together fairly well with widespread surficial cracks with some concrete spalling and evidence of corroding rebar. • Estimated Useful Life: Perhaps as little as 10 years, maybe as long as 25 years. (201 1 report) Two Primary Issues to Address 1) Maintaining the Structural Integrity of the Seawalls. ➢ New Seawall and/or Seawall Rehabilitation 2) Addressing the Current Water Over -Topping of the Walls and Planning for Future Sea Level Rise. ➢Top of Wall Elevation Issue 1: Maintaining the Structural Integrity of the Seawall When weighing the advantages of alternative construction options: new seawalls or seawall rehabilitation, some items to consider include: Condition of Existing Walls (approaching 90 years old) Expected Lifespan Cost - including Maintenance Seismic and Storm Endurance Liabilities and Exposure to a Failure 20 Grand Canal As -Built Condition GAgE� �AISV'�lD $�BA� CANAL CAP (W- EXTENSIONSI/ MANY LOCATIONSI SF)FWAI K TIE ROD PRECAST REINFORCED CONCRETE PANELS MINIMAL EMBEDMENT TIMBER DEADMEN PRECAST REINFORCED TEE SOLDIER PILES 11' TO 12' O.C. TYPICAL WALL CASES t1I OTHER NON.TYPICAL �umm�\c �V". 21 IV -3 T/2 West EndEEETPILE e._D. (E) CONCRETE SHEET PI AND CAP (TYP.) I As -Built ' I/{E) 1' ANCHOR ROD (TYPJ Condition - �1(E) CON EYES BOARDWALK WI E) TIMBER ANCHOR PILE (TP.) _ L I Constructed 1925-1935 Rock reinforcement installed 1985 CASE 2 - EXISTING CONDITION at WEST END New Seawall Construction — Option 1 H -Piles and Concrete Wall (Lag) Panels (No tiebacks) a .hx� ►.+, - f"rw ' ago - -ter H ,,_�w•q a � �+r. S _ Tf s - T� - .� - _ .ice •. ,��.�_ - i ' t dc r w :- _ pAd diAfpf'j;",. n r OWP � Its i1G'sn E�,WAI � - t -� } �AI F d # t ,-,. . L- 09/15/2014 r 1;> 09/15/2014 ,r 1 r 1;> 09/15/2014 YAN rl 3 ;a As for Seawall Replacement: NEW STEEL NAVD88 . DO'- Seawall 0_Seawall rehabilitation will be R� considered later in the oovf"° GEL C/P SYSTEMS presentation. (NOT SH0WN) -EXISTING TIMBER PILE DEADMEN I�ROPERTY UNE XISTING CONCRETE SOLDIER PILES (I) PER FLOW SIMULATION, LLC JUNE 18, 2010 GIVEN AS NAVDBB DATUM. OPTION 1 - NEW STEEL SHEET PILE SYSTEM G C & W E (WATERSIDE) 92 NEW SLURRY GROUT (STING SLURRY GROUT SEALER AP (NOT SHOWN FULLY Staff & TMC recommend the I FORCLAGRIC NGREE,E SHEETS walls. NEW CORRUGATED STEEL SHEET %LLS U ��XSPER:NCRNEETE steel sheet pile SOLDIER PILES • Slightly Lower(ROT C/P 5Y5 SHOWN) NOTE: TO I IST TIE R005 POVIDECCONTRACTOR PROVIDE CAPS d - - ARCHITECTURAL FINISH IST TIMBER PILE DEADMEN Construction Cost FORFAR KEY SLEEVE F SHEAR DDE 1'-10'3 ANGE 8'-0- TO 8'-8 PLAN • Much Less Disruption __--CORRUGATED SLEEVES (FOR FUTURE WALL EXTENSION) to Install EL 10.0' NAVDBB 1 -STET OF STUDS PER PAIR OF SHEET PILES ,.. -EXISTING TIE RODS NEW STEEL NAVD88 . DO'- Seawall 0_Seawall rehabilitation will be R� considered later in the oovf"° GEL C/P SYSTEMS presentation. (NOT SH0WN) -EXISTING TIMBER PILE DEADMEN I�ROPERTY UNE XISTING CONCRETE SOLDIER PILES (I) PER FLOW SIMULATION, LLC JUNE 18, 2010 GIVEN AS NAVDBB DATUM. OPTION 1 - NEW STEEL SHEET PILE SYSTEM G C & W E (WATERSIDE) 92 Issue 2: Addressing Current Water Over - Topping of the Seawalls and Planning for Future Sea Level Rise South Bay Front, 2005 I South Bay Front, 2005 •x South Bay Front, 2005 New Top of Wall Elevation Items to consider for selecting a new to • Potential of Flooding from: ✓ High Tide Levels ✓ Local Wind Waves ✓ Storm Surge ✓ Ocean Swell • Cost of Alternatives of wall elevation: ■ Ability and Estimated Time Intervals to Raise Cap Elevation • Ability to Store and Pump -Out Water • Liability and Exposure to Flooding • Maintaining Beach Access and Views Wall Elevation Study — Various Existing Conditions Top of Seawall Cap EL 7.7' to 7.8' Top of Boardwalk Ir EL 5.6' to 6.27 TOP 01 EL. 6 ToLO' of Seawall Cap EL 7.6' to B.3 Top of Boardwalk Top of Seawall Co EL. 6.4' to 7.3 Q 8.6 to 8.7 Top of Boardwalk EL. 6.3' to 6.67 Substandard Freeboard Southwest end of Balboa Island during a King Tide on December 12, 2013 with no storm surges or wind waves. 8.2' NAVD88 Overtopping Due To Storm Surge M, r South Bay Front Overtopping Due To High Tides and Wind Boat Waves (south gay Front, 2010) • :t .w r d'Yi N 8.2' NAVD88 � � J �^•yQ c�_,��_. -Gam:•?,^T -.r-r .. _. � _. .. - -4 ;_ . • - _ .�..__".11'.x. _ _ Hide Tide at north West End (zoos) U o� SWM •-m,m Li 1 T. •-m,m Li 1 �I ? Flooding at Balboa Island Ferry Landing (2005) Opr [Rio i —�,!Waft j -•i.�, �_.I .SIC ' - _= za. MOD staff mobilize portable emergency pumps to bail accumulating rain and over -topping flows. Street Flooding Overtopping Curb at Turquoise Avenue (December 22, 2010) alp j[. 41 Islands' Flood Potential It is a State requirement that our Coastal Projects consider potential sea level rise. The California Coastal Commission sea level rise guidance document recommends planning for as much as a 66 -inch rise by 2100. r Sea Level Rise Predictions — 2100 The "95%" column on the right side indicates that there is a 5% chance the predicted sea level rise will be exceeded. AY 5% 0% 95% gency ear o 5 0 0 (high confidence) IPCC 4th Assessment 2007 9" 15" 20" Vermeer and Rahmstorf 2009 39" 49" 61" US Corps of Engineers 2011 17" 39" 59" National Academy of Sciences 2012 17" 37" 66" IPCC 5th Assessment 2013 17" 24" 31" Quaternary Science Reviews 2014 28" 37" 47" Sea Level Rise Projections 7.0 -rj 0 5.0 0 N i $ 4.0 v v m 3.0 c m r a v 2.0 d 1.0 - COPC High ■ COPC Low • CA Coastal Conservancy — USACE / High USACE/Intermediate •••••• USACE/Low Vermeer and Rahmstorf Mean and Range Note: see text on Page 3.9 p1F� for descriptions of A IFI, A2, Bl and AR4 p 1 g1 • AR4 ■ .................. .... ..... .............................. 0.0,0,- 2010 .002010 2020 2030 2040 2050 2060 2070 Year 2080 2090 2100 44 Projected Sea Level Rise — 2100 • Mean sea level rise is expected to be in the range of 24-36 inches. • California State Coastal Conservancy (SCC) in 2009 adopts a Climate Change Policy that agencies should prepare for a 55 -inch sea level rise by 2100. (high confidence) • California Coastal Commission (2015) recommends planning for a 66 -inch sea level rise by 2100. Current Wall Heights - Flooding Potential: 2010 - Highest 1% (7) Tides with Wind Waves Scenario 04: Year 2010 / Tide p=Ol$ / Wind Waves 6059250 6059500 6051750 6060000 6060250 6060500 6060750 6061000 6061260 6061600 6061960 6062000 6062250 6062500 6062750 6063000 6063250 6063500 Current Wall Heights - Flooding Potential: 2010 Highest 10% (70) Tides Ocean Swell Scenario 03: Year 2010 / Tide p=10% / Ocean Swell 6059250 6059500 6059150 6060000 6060250 6060500 6060150 6061000 6061250 6061500 6061750 6062000 6062250 6062500 6062150 6063000 6063250 6063500 December 2010 Flooding on Turquoise Avenue: High Tide (p=40i) with Ocean Swell The Real Threat with a Flood is the Water Just Needs to Rise for an Instant and the Damage is Done Flooding Event, Balboa Avenue at Marina Avenue Looking East 49 Current Wall Heights - Flooding Potential: 2025 - Highest 1% Tides with Wind Waves Scenario 07: Year 2025 / Tide p=01% / Wind Waves Estimated Flooding Potential: 2025: Almost no flooding with 6" high sandbags. Scenario 12: Year 2025 / Tide p=01% / Wind Waves / Deployment of Sandbags Tidelands Management Committee Review (2011-2015) Many open public meetings with robust presentations and productive discussions. Discussions included review and guidance by URS Corporation consultant staff (Professional Marine Engineers). Active participation by Balboa Island Improvement Association and many Islands residents. Tidelands Management Committee Review Tidelands Committee members comments and direction lead to exploring several options for providing seawall structural stability and current/future flood protection including: Considering replacing all islands' seawalls with an initial top elevation of 10' now with ability to extend cap height up to 14' as needed in the future. Exploring the option of a major Tidal Gate structure option at Harbor Entrance. Suggesting several options of phased construction consisting of various degrees of seawall replacement or rehabilitation with incremental raising of the new and existing cap elevations to adjust as needed to rising sea levels. Tidelands Committee Guiding Direction Would like to get as much useful life/benefit out of existing seawalls. To minimize up front replacement cost, look at structural wall rehabilitation or other methods of support, and raising cap elevation on existing walls where it makes sense. Because there is a good deal of uncertainty associated with future sea level rise projections, raising wall height elevation should be kept as low as reasonable now to minimize impacts on beach access, related infrastructure cost (wall replacement, adjacent boardwalk, drainage system) and public and private views. Design all new walls to accommodate future extension of the cap elevation. Two Primary Issues to Address 1) Maintaining the Structural Integrity of the Seawalls. ➢ New Seawall and/or Seawall Rehabilitation 2) Addressing the Current Water Over -Topping of the Walls and Planning for Future Sea Level Rise. ➢Top of Wall Elevation Summary for Issue 1: Maintaining the Structural Integrity of the Seawalls. New seawalls are structurally sound and protective of seismic failure. Maintenance requirements are small. No easements required. Seawall rehabilitation reduces initial costs. Summary for Issue 2: Addressing Current Water Over -Topping of the Seawalls and Planning for Future Sea Level Rise 1. Seawall overtopping is occurring now. City crews must mobilize portable pumps to bail water out. 2. By 2025, a major storm could cause widespread flooding beyond the capability of City crews to provide emergency relief. Cars and low lying structures would could be flooded. Initial minimum top of wall elevation to provide normal over -topping flood protection until ^'2025. LOCATION Current New Difference Balboa Island N. Balboa Island S. Grand Canal Little Island E. 7.8' 8.5' +8.4 inches 8.25' 9.0' +9 inches 8.5' 8.5' 8.7' 8.7' Little Island S. 9.0' * all elevations based on NAVD88 datum. Important Note:These are minimum initial top -of -wall elevations to address conservative, high confidence projections of expected tides and wind waves. They do not take into account possible extreme conditions or Acts of God. 9.0' r", f.i Seawall Replacement Options Considered 10,352' new seawalls. $68 million Long Term 2,808' cap extensions. Rebuild most vulnerable seawalls (4,420 ft.). Cap $35 million Best Value extensions for remainder. Rebuild 640 ft. of seawall. Retrofit must vulnerable seawall. Cap extensions $17 million Short Term for the remainder. Retrofit must vulnerable. Cap extensions for the $14 million Short Term remainder. Option A: 10,352' of new seawalls. 2,808' cap extensions. Estimated cost $54 million 25% contingency 14 million Total $68 million Notes: I . Costs includes seawalls, caps, pier and beach access ramps, modifications to the entrance to the Ferry Landing and Collins Islands, and ADA modifications to the Boardwalk near the Mariner's Bridge. 2. Seawall cost are based on 2014 bids for the new seawalls in Naples, Long Beach. 3. Additional cost to extend cap 6 inches in 2025 to Elevation 95/9.0' (including Little Balboa Island): — $3 million. 4. Additional cost to replace 2,808' capped seawalls in 2040. with new seawalls and boardwalk: —$17 million (25% contingency). 4. Costs in today's dollars. 5. Elevation Datum: NAVD88 Option B: New Seawalls at West End and Grand Canal. Cap Extensions on Remaining Walls. NEW SEAWALL ON CAP EXTENSION, TOP OF WALL +9.0 FT NAVD88 CAP EXTENSION, TOP OF WALL +8.5 FT NAVD88 a Option B: Summary of Improvements New seawalls along entire length of West End: South side - Elev. 9.0' and North Side - Elev. 8.5'. New seawalls on both side of the Grand Canal (Elevation 8.5'). Raise seawall cap on South side of Balboa Island to Elevation 9.0'. Raise seawall cap on North side of Balboa Island to Elevation 8.5'. (Elevation Datum: NAVD88 ) Option B: Seawall Cap Extension Example on Little Balboa Island 63 Option 6: 4,420 Feet of New Seawalls plus Cap Extensions. Initial cost 25% contingency Project total Notes: $28 million 7 million $35 million i. Costs includes seawalls, caps, temporary pier and beach access ramps, modifications to the entrance to the Ferry Landing and Collins Islands, and ADA modifications to the Boardwalk near the Mariner's Bridge. 2. Seawall cost are based on 2014 bids for the new seawalls in Naples, Long Beach. 3. Additional cost to extend cap 6 inches in 2025 (including Little Balboa Island) to 9.0'/9.5': — $3 million 4. Additional cost to replace 8,740' of capped seawalls in 2040 with new seawalls and boardwalk: —$52 million (25% contingency) 5. Costs in today's dollars. 6. Elevation Datum: NAVD88 64 Option C: 1) 640' New Seawall at Southwest End of Balboa Island. 2) Seawall Rehabilitation or Cap Extension of Remainder. STRUCTURAL RETROFIT, TOP OF WALL +8.5 FT NAVD88 ©N NEW SEAWALL, TOP OF WALL +9.0 FT NAVD88 CAP EXTENSION, TOP OF WALL +9.0 FT NAVD88 CAP EXTENSION, TOP OF WALL +8.5 FT NAVD88 65 Grand Canal As -Built Condition �Bp�ISV`�y��,l . •III '. r,V �.,_ CAP (W EXTENSIONSl1 MANY LOCATIONS) TIE ROD SbEWALK TYPICAL WALL CASES C 1HER NONTYPICAL m ••:•'(" PRECAST REINFORCED - CONCRETE PANELS MINIMAL EMBEDMENT •' TMMBER DEADMEN f. PRECAST REINFORCED •.; y>•• TEE SOLDIER PILES 11TO 12' O.C. f,• TYPICAL WALL CASES C 1HER NONTYPICAL m Newport Marina Villas Townhomes ^'1995 Seawall Failure — Shallow Pile Embedment Grand Canal: Cap Veneer Spalled Option C: Structural Considerations for Seawall Rehabilitation 80 to 86 year-old walls. (Original lifespan approximately 75 years.) 1. Grand Canal Walls: a. Wall veneer is failing. b. Very shallow embedment (-2 to 3 feet). 2. West End: a. Floating sidewalks at high tide indicating leaks in the wall. b. Surficial signs of distress caused by current - induced shear stress and wave impacts. Option C: Earth Anchor and Tube Waler I ligh Temp S h, one Sealant a"c Hola Section 70 Bead of High Temp Silicone Sealant Grease 6'0 Pipe Sleove Injection Port O r Threaded Cap 12"x12'Stee O 12"x12'Steel Tube Tube Wale, clip & Water Epoxy Coated Cinch Achor Inside & Out (12 dry mills) Connection Details +/I (E) Cap i.'x t ,S2't teef rube Waler Elev. +2.00 4 I ligh Temp S h, one Sealant a"c Hola Section 70 Option C: Anchor installation requires easement. NOTE: As earth anchors ere installed, gout is continuously pumped through the drill head. therefore no voids are created during installation. Morning Canyon Erosion 18 9 months Control Project (2005) Buck Gully Erosion Control Project (201 1) Balboa Islands Seawall Project 23 18 months 93 E 71 Option C: Summary of Improvements . Balboa Island a. 640' of new seawalls at south West End b. 500' of seawall anchors/walers at north West End. (Easements required.) C. Raise cap on south side from 8.3' to 9.0' d. Raise cap on north side from 7.8' to 8.5' 2. Grand Canal (East and West Sides) a. Seawall anchors and walers. (Easements required.) b. No change in top of wall elevation. 3. Maintenance Requirements a. Annual inspections. b. Repairs as needed. C. Annual sand buttressing to maintain mudline elevation. 21 Dredging for Sand Buttressing - 1999 73 Annual Dredging for Sand Buttressing Grand Canal (E) Residential P and Piles (typ_) Sidecast Original Assumption of Mudline Height Based on Wall Stability (from original drawings) Dredge (E) Seawall Panel (E) Seawall Cap (E) Boardwalk (E) Tie Rod (E) Timber Anchor Pile (E) Reinforced Concrete Soldier Pile Option C: Cost Summary Improvements Enhanced maintenance (20 years) 25% Contingency $8.2 million 5.0 million 3.3 million TOTAL $16.5 million Notes: I . Costs includes seawalls, caps, temporary pier and beach access ramps, modifications to the entrance to the Ferry Landing and Collins Islands, and ADA modifications to the Boardwalk near the Mariner's Bridge. 2. Cost to extend cap 6 inches in 2025 to Elevation 9.0'/9.5': — $6.5 million 3. Cost to replace capped seawalls (in 2030-2040) when needed: $75+ million 4. Costs in today's dollars. 5. Elevation Datum: NAVD88 75 Final Notes: Higher Risks Associated with Option C Rehabilitation methodology is not protective per current seismic standards. The shallow embedment of the walls in the Grand Canal put them at high risk of blow-out from seismically -induced liquefaction. No line item has been added for emergency mobilization and repair. Installation of anchors can damage existing walls. No line item has been added for a localized repair or replacement. Over the next 25 years, future settling, cracking, plumbing leaks, etc. of houses could be claimed to be attributable to the seawall rehabilitation. No line item has been allocated for potential claims. Option D: Seawall rehabilitation in Grand Canal and West End. Cap extensions for the remaining walls. --..,.. -..,., , - STRUCTURAL RETROFIT ©N CAP EXTENSION, TOP OF WALL +9.0 FT NAVD88 CAP EXTENSION, TOP OF WALL +8.5 FT NAVD88 77 Option D: Cost Summary Improvements Enhanced maintenance (20 years) 25% contingency TOTAL Notes: $5.9 million 5.0 million 2.7 million $13.6 million I . Wall integrity testing required as in Option C. 2. Costs includes seawalls, caps, temporary pier and beach access ramps, modifications to the entrance to the Ferry Landing and Collins Islands, and ADA modifications to the Boardwalk near the Mariner's Bridge. 3. Cost to extend cap 6 inches in 2025 to Elevation 9.0'/9.5': — $7.5 million 4. Cost to replace capped seawalls in (2030-2040) when needed: $79+ million 5. Costs in today's dollars. 6. Elevation Datum: NAVD88 m COSI Sum ma ry (Immediate Costs) OPTION INITIAL EXPECTED USEFUL COST LIFE A. All new seawalls (10,352) $68 million' 100 years B. 4420' of new seawalls (Grand Canal $35 million1,2 100 years/25years and West End) + cap extensions C. 640' of new seawall at south West End + Seawall rehab. of Grand Canal $17 million1,2 100 years/10-20 years and north West End + cap extensions + enhanced maintenance D. Seawall rehabilitation of West End and Grand Canal + cap extensions + $14 million1,2 10-20 years enhanced maintenance Notes: 1. Costs for cap extensions (2025, 2040) not included. 2. Costs for new wall construction (2030-2040) not included. Comparison of Options B and C Initial cost (2020) Easements required? Cap extensions (2025) Replace capped walls with new seawalls (2040) $35 million $16.5 million No Yes. Delay of construction initiation significantly heightened. $3 million $6.5 million $52 million $75+ million Total Cost (present worth) $90 million $98 million If rehabilitation works for 20 years If rehabilitation does not work Risk of seismic failure Obtained maximum mileage from seawalls. Investment in anchoring system wasted. Emergency repair costs. Property damage claims. Low, but higher High than Option A. Overall risk of structural 1-2 5-10 failure: I (low risk) -10 i Preliminary Schedule .. . Design, CEQA, Permits Sept 2015 — Sept 2016 for Cap Extension Cap Construction April 2017 — Dec 2017 Easement for Anchors Design, CEQA, Permits for New Seawall or Seawall Rehabilitation Sept 2015 — Sept 2018 A Sept 2015 — Sept 2016 April 2017 —Dec 2017 Sept 2015 — Dec 2016 Jan 2017 — Jan 2020 New Seawall or Seawall Oct 2018 — March 2020 April 2020 —April 2021 Rehabilitation Construction PresentValue CostAnalysis Phase - Years to Start Option A Option B Option C Option D Phase I - 5 Years to Start Phase II - 10 Years to Start Phase III - 25 Years to Start Total Cost Over 25 yrs 68,000,000 3,000,000 17,000,000 88,000,000 35,000,000 3,000,000 52,000,000 90,000,000 16,500,000 6,500,000 75,000,000 13, 600, 000 7,500,000 79, 000, 000 98,000,000 100,100,000 139,893,224 128,871,428 146,139,949 150,570,196 Present Value Cost Est. 94,515,708 90,000,000 98,000,000 100,100,000 NOTES: I. All options assume future costs to inflate by 3% per year. 2. All options assume a long-term investment earning rate (discount rate) is also 3%. 3. Options A & B assume Phase I is cash funded with $22.1 million with the balance financed. 4. Option A assumes a balance of $56.7 million financed over 20 years at 4.55%. S. Option B assumes a balance of $18.5 million financed over 10 Years at 3%. 6. Options C & D assumes Phase I is entirely cash funded. 7. All options assume Phase II & III is cash funded. 82 Funding History &Result Tidelands Master Plan —Prioritized Projects Tidelands Capital Fund Created to fund Harbor Amenities on Tidelands Master Plan Source: Incremental Rents from Residential Docks Commercial Marinas Moorings $15 Million Advanced for Dredging & Marina Dock and Mooring Rents Reduced Fewer funds available for Harbor Amenities Harbor Capital Fund Owes General Fund $15.8 million Dredging $9.7 Million Marina Park marina $6.1 Million 15 Year Repayment Schedule thru 2030 After malting annual repayment to General Fund, Harbor Capital Fund expected to net $500K annually available for Harbor Amenities Funding Options . Consider Special Benefit Assessment 2. Convert Marine & Park Ave to paid parking 3. Use Available Proceeds in Harbor Capital Fund (may squeeze out harbor amenities) 4. Save $3-5 million per year in addition to Paid Parking (may squeeze out services) :�. Reduce Contributions to (FFP) Facilities Replacement Plan (may obstruct projects) 6. Internal loan — From General Fund Contingency (may increase exposure) Finance balance, as necessary QUESTIONS &COMMENTS 9, F�I Public Works Department A Well -Engineered Machine Protecting and Providing Quality Public Improvements and Services Appendices 1) Ferry Landing Concepts 2) Tide Gate at Harbor Jetty Concept 3) Storm Dain Collection System Concepts 4) ADA and Beach Access Concepts s) Public & Private Pier Connections Concepts 6) FEMA Flood Plain Reviewed Potential for a Tide Gate at the Harbor Jetty: See City website for May 29, 2014 PowerPoint presentation. I1 LLP.// i I'eyypUI LUtfd .I ILd.AUV/° IIUIII Reviewed Potential for a Tide Gate at the Harbor Jet Summary on Harbor Tide Gate Estimated installation cost of $350 million or more. Design is dependent on the magnitude of sea level rise. Will have some level of operational effects on harbor entrance. Will not resolve structural concerns of the existing Balboa Island seawalls. Will not resolve water coming through and over the Peninsula. Tide Gate at Harbor Jetty: Staff Recommendations Approved by Tidelands Management Committee: 1. Verify sea level rise predictions y By about 2020, king tides could be 2-3 inches higher than today — on track for a 66" rise in sea level by 2100. 2. Set new harbor -wide standard for top of seawall elevation, e.g., 10 feet NAvoss 3. Set new requirements for finish floor elevations for new construction and/or major remodels. Ferry Landing — Concept 1 Boardwalk and Street Ramps NEW PUBLIC l BOARDWALK RAMP r 6.27 (N( NEW STREET RAMPAND SIDEWALKS 7 9.72 (N) 9.90 (N) 76' 1 6.0 (E) NEW BOA RAM 1 a Ferry Landing — Concept 2: Diverted Walking Path ear 29' y � 1 PUBLIC WALKING PATHWAY TO MATCH EXIST. PAVEMENT 5.19 (E) PUBLIC WALKING PATHWAY EXISTING PUBM/ ��/iii/�%ice EXISTING PUBLIC BOARDWALK iTREET RAM 3 : At 93 Balboa Island Ferry Modification - - Concept 3 Section A -A' ME Option 3 e e8p w Damm: NAVD 88 e Street End Flooding when Tide Gate Closed Existing Drainage System on Balboa Island INS BALBOA ND f O WAP ;�W e 3' jP P t` 1 ' r BALSOAAVE P i ¢ < V < <l A4 N RRAYE j p P iii `OP1 iW 4Y 3 JJ� � J BALBOA ISLAND Tide Valves Protects the Island from Flooding due to High Tides Currently Manually Operated Manually Operated with Valve Key Power Assisted with Manually Operated Up/Down Switch New Rubber Tide Valve (Check Valve) ➢ No Moving Mechanical Parts - Silent, Non -Slamming ➢ Non—Corrosive - Durable Rubber Construction ➢ Minimal Maintenance and Periodic Inspection Needed ➢ Around 1" of Water Pressure Opens Valve helping Eliminate Standing Water ➢ Simple Installation. Estimated 25 -Year Life Low Flow Open Full Flow Open Closed Against Tide NEW DRAINGE SYSTEM CONCEPT OP A. j ^ w u CONSOLIDATE GRAVITY DISCHARC POINT WITH AUTO TIDE GATE AND PUMP STATION BACK UP PARK z U Y 'RONT SOUTH ➢ Reduce Number of Discharge Points ➢ Automate Tide Values ➢ Provide High Water Pump -Out Capacity IN Sub -Terrain Storm Water Pump Station Public Pier and Beach Access w Balboa Islands and ., Floodplain Management Information Please see the City's webpage: http://newportbeachca.gov/home/showdocument?id=156 33 r Proposed z w Steps Over Extended y Cap ANCHOR/SEAL -\ PLAN FIBERGLAS OR WOOD STEPS EL +9.0' NAVIM I I _______ I I I RESIDENTIAL PIE I I I I I I _1 UrLl_ ANCHOR AND/OR OTHER MECHANISM TO ATTACH AND SEAL PLATE TO CAP SECTION B -B OR HYBRID EXTENSION OF CAP DETAIL A - CONCEPT (Steps Over Cap Extensions) :.RETE CAP NSION ;AP TO REMAIN -BOAROWAUK :RETE CAP NSION CAP BEYOND .(E) CAP TO REMAIN BOARDWALK (E) BULKHEAD (SOLDIER PILE W/ LAGGING SHOWN) 102 ON EXTI RESIDENTIAL PIER r----- -------------------- I I I I I I I I I I I I E) I I I I I I I I I I I I L I I I I I L" -fl BERGLA55 aR WOOD STEPS I I I I CON I I I I I I EXTI I I I ir� STEEL OR HYBRI PLATE EXTENSION OF CAP PLAN FIBERGLAS OR WOOD STEPS EL +9.0' NAVIM I I _______ I I I RESIDENTIAL PIE I I I I I I _1 UrLl_ ANCHOR AND/OR OTHER MECHANISM TO ATTACH AND SEAL PLATE TO CAP SECTION B -B OR HYBRID EXTENSION OF CAP DETAIL A - CONCEPT (Steps Over Cap Extensions) :.RETE CAP NSION ;AP TO REMAIN -BOAROWAUK :RETE CAP NSION CAP BEYOND .(E) CAP TO REMAIN BOARDWALK (E) BULKHEAD (SOLDIER PILE W/ LAGGING SHOWN) 102 Beach Access Concept 103 (E) CONCRETE CAP CONCRETE CAP EXTENSION OI pPe` 0 STEEL OR HYBRID PLATE EXTENSION ^- rAm FIBERGLASS f OR WOOD STEPS Option C: Enhanced Testing Program Cost Cost for core samples, lab tests, report, and presentation at Grand Canal & West End Only: Sampling at approx. 200 foot intervals Samples at various heights (e.g., low, mid and top) $150,000 to $200,000 Option C: Enhanced Testing Program Coring Samples 2" — 3" diameter samples — full penetration 3 cores per panel at 200' intervals 3 cores per soldier pile at 200' intervals Thin part of soldier piles only 8" — 10" wide 65 core samples for Grand Canal & West End 200 core samples for entire island Concerns: Core samples/reinforcing adjacency, un -sampled areas.